Does hyperemesis gravidarum affect the fetus?

Hyperemesis gravidarum is associated with an increased risk of preterm birth, (<34 weeks) and very severe cases of hyperemesis gravidarum can affect the growth and development of the fetus. This may increase the risk of having a small for gestational age or low birth weight infant.^[1] However, some studies find that these risks are only present when maternal weight loss is significant, and there is no “catch up” weight gain later in pregnancy. In other words, if prepregnancy weight is normal, and weight loss in the first trimester is attenuated by regaining weight throughout the latter part of pregnancy, there is no significantly increased risk of fetal growth restriction.^[2][3] There are few studies investigating the long-term risks of hyperemesis gravidarum to the infant, and the studies that do exist are of low quality. It is possible that children born to parents with hyperemesis gravidarum are at an increased risk of developing anxiety disorders, sleep disorders, testicular cancer, and neurodevelopmental disorders, like autism spectrum disorder and attention deficit hyperactivity disorder, but the data is not robust or consistent enough to make strong conclusions about long-term risks.^[4]